title: Bifunctional silica nanoparticles for the exploration of biofilms of Pseudomonas aeruginosa.
abstract: Luminescent silica nanoparticles are frequently employed for biotechnology applications mainly because of their easy functionalization, photo-stability, and biocompatibility. Bifunctional silica nanoparticles (BSNPs) are described here as new efficient tools for investigating complex biological systems such as biofilms. Photoluminescence is brought about by the incorporation of a silylated ruthenium(II) complex. The surface properties of the silica particles were designed by reaction with amino-organosilanes, quaternary ammonium-organosilanes, carboxylate-organosilanes and hexamethyldisilazane. BSNPs were characterized extensively by DRIFT, (13)C and (29)Si solid state NMR, XPS, and photoluminescence. Zeta potential and contact angle measurements exhibited various surface properties (hydrophilic/hydrophobic balance and electric charge) according to the functional groups. Confocal laser scanning microscopy (CLSM) measurements showed that the spatial distribution of these nanoparticles inside a biofilm of Pseudomonas aeruginosa PAO1 depends more on their hydrophilic/hydrophobic characteristics than on their size. CLSM observations using two nanosized particles (25 and 68 nm) suggest that narrow diffusion paths exist through the extracellular polymeric substances matrix.
authors.affiliation: Centre Interuniversitaire de Recherche et de l'Ingénierie des Matériaux, UMR-CNRS 5085, Université Paul Sabatier, Toulouse cedex 9, France.
authors.forename: L
authors.initials: L
authors.lastname: Mauline
authors.forename: M
authors.initials: M
authors.lastname: Gressier
authors.forename: C
authors.initials: C
authors.lastname: Roques
authors.forename: P
authors.initials: P
authors.lastname: Hammer
authors.forename: S J L
authors.initials: SJ
authors.lastname: Ribeiro
authors.forename: J M A
authors.initials: JM
authors.lastname: Caiut
authors.forename: M-J
authors.initials: MJ
authors.lastname: Menu
mesh_terms: D018441:Biofilms; D057219:Biofouling; D053758:Nanoparticles / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D017975:Ruthenium Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D017975:Ruthenium Compounds; D012822:Silicon Dioxide